Overview
- More than 18 million people are under winter weather alerts across the West and Midwest as heavy mountain snow continues in the Northern Rockies and snow spreads into the Upper Midwest.
- Fast‑moving clipper systems are laying down a trace to 1–2 inches of snow, locally up to 3 inches, setting up slick spots for the Monday morning commute in parts of the Great Lakes, Northeast and Mid‑Atlantic.
- Monday and Tuesday turn bitter, with highs stuck in the 20s or colder and wind chills in the single digits or below zero, including subzero starts in interior Northern New England and the Upper Midwest.
- The Pacific Northwest faces rounds of heavy rain from successive Pacific storms, with saturated ground, flood watches posted, and an elevated risk for flash flooding in western Washington and Oregon.
- Temperatures moderate briefly midweek as a stronger system brings a rain‑snow mix Tuesday night into Wednesday for some regions before another push of colder air arrives late week.